questions on my new SBT engine...

[Texwing]

Hi, I am running a new SBT engine on my 1995 sts 750 kawasaki, and i am still trying to insure I am tuning it correctly...

I have gone to premix and thought I was to use a 40:1 premix ration, but then read elsewhere on this sight that Kawasaki's use 50:1?

It would be useful to know what kind of rpm's I should expect from this engine when running correctly; right now it will do about 5900 at WOT, and its not changing as I continue to turn the high speed adjuster in...But I may still be rich, I am 7/8 turns out, factory spec is 3/4 turns out, plus or minus 1/4 turn.

Would I expect a jump in rpms when getting close to the right setting? Reading the plugs is not as easy as presented, I have done the 20 second WOT runs, and it is just not clear what I am seeing, we have only methanol gas down here and perhaps that is affecting what I am seeing. thanks for any comments.

[Technical Support]

Re: questions on my new SBT engine...

40:1 is the best choice, How is your ski running otherwise? Has the ski ever had the impeller changed?

[Texwing]

Re: questions on my new SBT engine...

40:1 is the best choice, How is your ski running otherwise? Has the ski ever had the impeller changed?

No, I dont think the impeller has ever been touched, but I was assuming (but dont know) that a worn impeller/wear ring would promote higher rpm with less thrust.

Shortly before my last engine disintergrated (bad fuel pump diaphram, I think) it was turning just a shade under 6100 rpm, so i know the potential is there unless a lean engine on the verge of blowing will turn higher revs...

So, i started the high speed adjustement at 1 and 1/4 turn out..Looked wet and oily, and rich. Factory spec is either 3/4 turn out for a 95, or 1 1/8 turn out for a 96. (mine is titled a 95, who knows for sure...) At 1 and 1/8 it was no longer wet but had black goo on it, and from there I just could not get much of a read on the 20 second WOT test. I look at the pics and see nice rich coloring, but I am just not seeing that on my plugs-I don't see much of anything but some small specs of the black goo.

It runs well right now, but just does not seem to have much top end grunt. I am still wondering if finding the magic spot will suddenly yield a couple of extra hundred rpm and noticable power, or not- otherwise i might just leave where I know its rich. thanks for the help.